Pellicles for photomasks, reticles including the photomasks, and methods of manufacturing the pellicles

ABSTRACT

A pellicle configured to protecting a photomask from external contaminants may include a metal catalyst layer and a pellicle membrane including a 2D material on the metal catalyst layer, wherein the metal catalyst layer supports edge regions of the pellicle membrane and does not support a central region of the pellicle membrane. The metal catalyst layer may be on a substrate, such that the substrate and the metal catalyst layer collectively support the edge region of the pellicle membrane and do not support the central region of the pellicle membrane. The pellicle may be formed based on growing the 2D material on the metal catalyst layer and etching an inner region of the metal catalyst layer that supports the central region of the formed pellicle membrane.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.16/004,585, filed Jun. 11, 2018, which claims the benefit, under 35U.S.C. § 119, of Korean Patent Application Nos. 10-2017-0097125, filedon Jul. 31, 2017 and 10-2018-0065906, filed on Jun. 8, 2018, in theKorean Intellectual Property Office, the disclosure of each of which isincorporated herein in its entirety by reference.

BACKGROUND 1. Field

The present disclosure relates to pellicles for photomasks, reticlesincluding the photomasks, and methods of manufacturing the pellicles forphotomasks.

2. Description of the Related Art

A pellicle may be provided on a photomask to protect the photomask fromexternal contaminants (for example, dust, resists, etc.) in an opticallithography process. The pellicle should have a high transmittance withrespect to light used in the lithography process and also satisfyvarious conditions such as heat dissipation characteristics, strength,uniformity, durability, stability, etc. As a line-width of semiconductordevices/electronic circuits is reduced, wavelength of light used in thelithography process may be reduced to match the reduced line-width.

SUMMARY

Some example embodiments include a pellicle material suitable for alight source used in the optical lithography process.

Some example embodiments include pellicles configured to protectphotomasks from external contaminants, reticles including thephotomasks, and methods of manufacturing the pellicles for photomasks.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to some example embodiments, a pellicle configured to protecta photomask may include a substrate, a metal catalyst layer on thesubstrate, and a pellicle membrane on the metal catalyst layer. Thepellicle membrane may include a two-dimensional (2D) material. Thepellicle membrane may have a central region and an edge region, the edgeregion at least partially surrounding the central region. The substrateand the metal catalyst layer may collectively support the edge region ofthe pellicle membrane and may not support the central region of thepellicle membrane.

The metal catalyst layer may have a thickness in a range from about 10nm to about 100 μm.

The metal catalyst layer may have a thickness in a range from about 10nm to about 10 μm.

The pellicle may further include a barrier layer between the substrateand the metal catalyst layer.

The barrier layer may include at least one of SiO₂, Si₃N₄, TiN, and TaN.

The 2D material may include at least one of h-BN, Si, P, B, andgraphene.

The pellicle membrane may have a thickness in a range from about 5 nm toabout 50 nm.

The metal catalyst layer may include at least one of Pt, Cu, Ni, Co, Ag,W, Mo, Pd, and Ru.

The pellicle membrane may have an optical transmittance of greater thanor equal to about 80%.

A sum of a height of the metal catalyst layer and a height of thesubstrate may be in a range from 1 mm to 10 mm.

The pellicle for a photomask may further include a protection film on atleast one surface of the pellicle membrane.

The protection film may include at least one of a carbon-based material,a transition metal dichalcogenide (TMD), Ru, Mo, Si, Zr, B, and SiN.

According to some example embodiments, a method of manufacturing apellicle configured to protect a photomask may include forming a metalcatalyst layer on a substrate, forming a pellicle membrane on the metalcatalyst layer, and etching inner regions of the substrate and the metalcatalyst layer that support the central region of the pellicle membrane,such that the substrate and the metal catalyst layer collectivelysupport the edge region of the pellicle membrane and do not support thecentral region of the pellicle membrane. The pellicle membrane mayinclude a two-dimensional (2D) material. The pellicle membrane mayinclude a central region and an edge region, the edge region at leastpartially surrounding the central region.

The method may further include forming a barrier layer on the substrate.

The method may further include forming a protection film on at least onesurface of the pellicle membrane.

The forming of the pellicle membrane may include forming the pelliclemembrane directly on a surface of the metal catalyst layer.

The etching may include etching the substrate and the metal catalystlayer based on using at least one of a mechanical etching method, a dryetching method, and a wet etching method.

According to some example embodiments, a method of manufacturing apellicle configured to protect a photomask may include forming a barrierlayer on a substrate, forming a metal catalyst layer on the barrierlayer, forming a pellicle membrane between the metal catalyst layer andthe barrier layer, removing the metal catalyst layer, and etching innerregions of the substrate and the barrier layer that support the centralregion of the pellicle membrane, such that the substrate and the barrierlayer collectively support the edge region of the pellicle membrane anddo not support the central region of the pellicle membrane. The pelliclemembrane may include a two-dimensional (2D) material. The pelliclemembrane may have a central region and an edge region, the edge regionat least partially surrounding the central region.

The method may further include forming a protection film on at least onesurface of the pellicle membrane.

Each of the removing of the metal catalyst layer and the etching of thesubstrate and the barrier layer may be performed based on using at leastone of a mechanical etching method, a dry etching method, and a wetetching method.

According to some example embodiments, a reticle may include a photomaskand a pellicle. The photomask may include a mask pattern. The pelliclemay include a substrate, a metal catalyst layer on the substrate andsurrounding the mask pattern, and a pellicle membrane including atwo-dimensional (2D) material. The pellicle membrane may include acentral region and an edge region. The edge region may at leastpartially surround the central region. The edge region may be supportedby the substrate and the metal catalyst layer, and the central regionmay be unsupported by the substrate and the metal catalyst layer.

The photomask may be spaced apart from the pellicle membrane by adistance in a range from about 1 mm to about 10 mm.

The metal catalyst layer may have a thickness in a range from about 10nm to about 100 μm.

The metal catalyst layer may have a thickness in a range from about 10nm to about 10 μm.

The pellicle may further include a barrier layer between the substrateand the metal catalyst layer.

The barrier layer may include at least one of SiO₂, Si3N4, TiN, and TaN.

The 2D material may include at least one of h-BN, Si, P, B, andgraphene.

The pellicle membrane may have a thickness in a range from about 5 nm toabout 50 nm.

The metal catalyst layer may include at least one of Pt, Cu, Ni, Co, Ag,W, Mo, Pd, and Ru.

The pellicle membrane may have an optical transmittance greater than orequal to about 80%.

The pellicle may further include a protection film on at least onesurface of the pellicle membrane.

The protection film may include at least one of a carbon-based material,a transition metal dichalcogenide (TMD), Ru, Mo, Si, Zr, B, and SiN.

According to some example embodiments, a pellicle configured to protecta photomask may include a metal catalyst layer and a pellicle membraneon the metal catalyst layer. The pellicle membrane may include atwo-dimensional (2D) material. The pellicle membrane may have a centralregion and an edge region. The edge region may at least partiallysurround the central region. The metal catalyst layer may support theedge region of the pellicle membrane and may not support the centralregion of the pellicle membrane.

The pellicle may further include a substrate, where the metal catalystlayer is on the substrate, and where the substrate and the metalcatalyst layer collectively support the edge region of the pelliclemembrane and do not support the central region of the pellicle membrane.

The pellicle may further include a barrier layer between the substrateand the metal catalyst layer.

The barrier layer may include at least one of SiO₂, Si₃N₄, TiN, and TaN.

A sum of a height of the metal catalyst layer and a height of thesubstrate may be in a range from about 1 mm to about 10 mm.

The metal catalyst layer may have a thickness in a range from about 10nm to about 100 μm.

The metal catalyst layer may have a thickness in a range from about 10nm to about 10 μm.

The 2D material may include at least one of h-BN, Si, P, B, andgraphene.

The pellicle membrane may have a thickness in a range from about 5 nm toabout 50 nm.

The metal catalyst layer may include at least one of Pt, Cu, Ni, Co, Ag,W, Mo, Pd, and Ru.

The pellicle membrane may have an optical transmittance greater than orequal to about 80%.

The pellicle may further include a protection film on at least onesurface of the pellicle membrane.

The protection film may include at least one of a carbon-based material,a transition metal dichalcogenide (TMD), Ru, Mo, Si, Zr, B, and SiN.

According to some example embodiments, a method of manufacturing apellicle configured to protect a photomask may include forming apellicle membrane on a metal catalyst layer. The pellicle membrane mayinclude a two-dimensional (2D) material. The pellicle membrane mayinclude a central region and an edge region. The edge region may atleast partially surround the central region. The method may furtherinclude etching at least an inner region of the metal catalyst layerthat supports the central region of the pellicle membrane, such that themetal catalyst layer supports the edge region of the pellicle membraneand does not support the central region of the pellicle membrane.

The method may further include forming the metal catalyst layer on asubstrate, wherein the etching etches inner regions of the substrate andthe metal catalyst layer that support the central region of the pelliclemembrane, such that the substrate and the metal catalyst layercollectively support the edge region of the pellicle membrane and do notsupport the central region of the pellicle membrane.

The method may further include forming a barrier layer on the substrate.

The method may further include forming a protection film on at least onesurface of the pellicle membrane.

The forming of the pellicle membrane may include forming the pelliclemembrane directly on a surface of the metal catalyst layer.

The etching of the metal catalyst layer may include etching the metalcatalyst layer based on using at least one of a mechanical etchingmethod, a dry etching method, and a wet etching method.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a schematic cross-sectional view of an exposure apparatusaccording to some example embodiments of the inventive concepts;

FIG. 2 is a cross-sectional view of a pellicle for a photomask,according to some example embodiments of the inventive concepts;

FIG. 3A, FIG. 3B, FIG. 3C, and FIG. 3D are cross-sectional views forexplaining a method of manufacturing a pellicle for a photomask,according to some example embodiments of the inventive concepts;

FIG. 4 is a cross-sectional view of a pellicle for a photomask,according to some example embodiments of the inventive concepts;

FIG. 5A, FIG. 5B, FIG. 5C, FIG. 5D, and FIG. 5E are cross-sectionalviews for explaining a method of manufacturing a pellicle for aphotomask, according to some example embodiments of the inventiveconcepts;

FIG. 6 is a cross-sectional view of a pellicle for a photomask,according to some example embodiments of the inventive concepts;

FIG. 7A, FIG. 7B, FIG. 7C, FIG. 7D, FIG. 7E, and FIG. 7F arecross-sectional views for explaining a method of manufacturing apellicle for a photomask, according to some example embodiments of theinventive concepts; and

FIG. 8A, FIG. 8B, and FIG. 8C are cross-sectional views for explaining amethod of manufacturing a pellicle for a photomask, according to someexample embodiments of the inventive concepts.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings so that those of ordinaryskill in the art may readily understand. Also, it should be understoodthat the embodiments may be realized in various ways, and thus, theinventive concepts are not limited to the embodiments described above.In the drawings, portions irrelevant to the description are omitted forconvenience of explanation, and like reference numerals are used toindicate elements that are similar to each other throughout thespecification.

It should be understood that, when the specification describes that apart “comprises” or “includes” an element, unless otherwise defined,other elements are not excluded from the part and the part may furtherinclude other elements.

Although the terms “first,” “second,” “third,” etc., may be used hereinto describe various elements, components, regions, layers, and/orsections, these elements, components, regions, layers, and/or sections,should not be limited by these terms. These terms are only used todistinguish one element, component, region, layer, or section, fromanother region, layer, or section. Thus, a first element, component,region, layer, or section, discussed below may be termed a secondelement, component, region, layer, or section, without departing fromthe scope of this disclosure.

Spatially relative terms, such as “beneath,” “below,” “lower,” “under,”“above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below,” “beneath,” or“under,” other elements or features would then be oriented “above” theother elements or features. Thus, the example terms “below” and “under”may encompass both an orientation of above and below. The device may beotherwise oriented (rotated 90 degrees or at other orientations) and thespatially relative descriptors used herein interpreted accordingly. Inaddition, when an element is referred to as being “between” twoelements, the element may be the only element between the two elements,or one or more other intervening elements may be present.

As used herein, the singular forms “a,” “an,” and “the,” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes,” and/or “including,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups, thereof. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items. Expressions such as “at least oneof,” when preceding a list of elements, modify the entire list ofelements and do not modify the individual elements of the list. Also,the term “exemplary” is intended to refer to an example or illustration.

When an element is referred to as being “on,” “connected to,” “coupledto,” or “adjacent to,” another element, the element may be directly on,connected to, coupled to, or adjacent to, the other element, or one ormore other intervening elements may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to,”“directly coupled to,” or “immediately adjacent to,” another elementthere are no intervening elements present.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and/or this disclosure, and should notbe interpreted in an idealized or overly formal sense unless expresslyso defined herein.

Example embodiments may be described with reference to acts and symbolicrepresentations of operations (e.g., in the form of flow charts, flowdiagrams, data flow diagrams, structure diagrams, block diagrams, etc.)that may be implemented in conjunction with units and/or devicesdiscussed in more detail below. Although discussed in a particularlymanner, a function or operation specified in a specific block may beperformed differently from the flow specified in a flowchart, flowdiagram, etc. For example, functions or operations illustrated as beingperformed serially in two consecutive blocks may actually be performedsimultaneously, or in some cases be performed in reverse order.

Units and/or devices according to one or more example embodiments may beimplemented using hardware, software, and/or a combination thereof. Forexample, hardware devices may be implemented using processing circuitysuch as, but not limited to, a processor, Central Processing Unit (CPU),a controller, an arithmetic logic unit (ALU), a digital signalprocessor, a microcomputer, a field programmable gate array (FPGA), aSystem-on-Chip (SoC), a programmable logic unit, a microprocessor, orany other device capable of responding to and executing instructions ina defined manner.

Software may include a computer program, program code, instructions, orsome combination thereof, for independently or collectively instructingor configuring a hardware device to operate as desired. The computerprogram and/or program code may include program or computer-readableinstructions, software components, software modules, data files, datastructures, and/or the like, capable of being implemented by one or morehardware devices, such as one or more of the hardware devices mentionedabove. Examples of program code include both machine code produced by acompiler and higher level program code that is executed using aninterpreter.

For example, when a hardware device is a computer processing device(e.g., a processor, Central Processing Unit (CPU), a controller, anarithmetic logic unit (ALU), a digital signal processor, amicrocomputer, a microprocessor, etc.), the computer processing devicemay be configured to carry out program code by performing arithmetical,logical, and input/output operations, according to the program code.Once the program code is loaded into a computer processing device, thecomputer processing device may be programmed to perform the programcode, thereby transforming the computer processing device into a specialpurpose computer processing device. In a more specific example, when theprogram code is loaded into a processor, the processor becomesprogrammed to perform the program code and operations correspondingthereto, thereby transforming the processor into a special purposeprocessor.

Software and/or data may be embodied permanently or temporarily in anytype of machine, component, physical or virtual equipment, or computerstorage medium or device, capable of providing instructions or data to,or being interpreted by, a hardware device. The software also may bedistributed over network coupled computer systems so that the softwareis stored and executed in a distributed fashion. In particular, forexample, software and data may be stored by one or more computerreadable recording mediums, including the tangible or non-transitorycomputer-readable storage media discussed herein.

According to one or more example embodiments, computer processingdevices may be described as including various functional units thatperform various operations and/or functions to increase the clarity ofthe description. However, computer processing devices are not intendedto be limited to these functional units. For example, in one or moreexample embodiments, the various operations and/or functions of thefunctional units may be performed by other ones of the functional units.Further, the computer processing devices may perform the operationsand/or functions of the various functional units without sub-dividingthe operations and/or functions of the computer processing units intothese various functional units.

Units and/or devices according to one or more example embodiments mayalso include one or more storage devices. The one or more storagedevices may be tangible or non-transitory computer-readable storagemedia, such as random access memory (RAM), read only memory (ROM), apermanent mass storage device (such as a disk drive), solid state (e.g.,NAND flash) device, and/or any other like data storage mechanism capableof storing and recording data. The one or more storage devices may beconfigured to store computer programs, program code, instructions, orsome combination thereof, for one or more operating systems and/or forimplementing the example embodiments described herein. The computerprograms, program code, instructions, or some combination thereof, mayalso be loaded from a separate computer readable storage medium into theone or more storage devices and/or one or more computer processingdevices using a drive mechanism. Such separate computer readable storagemedium may include a Universal Serial Bus (USB) flash drive, a memorystick, a Blu-ray/DVD/CD-ROM drive, a memory card, and/or other likecomputer readable storage media. The computer programs, program code,instructions, or some combination thereof, may be loaded into the one ormore storage devices and/or the one or more computer processing devicesfrom a remote data storage device via a network interface, rather thanvia a local computer readable storage medium. Additionally, the computerprograms, program code, instructions, or some combination thereof, maybe loaded into the one or more storage devices and/or the one or moreprocessors from a remote computing system that is configured to transferand/or distribute the computer programs, program code, instructions, orsome combination thereof, over a network. The remote computing systemmay transfer and/or distribute the computer programs, program code,instructions, or some combination thereof, via a wired interface, an airinterface, and/or any other like medium.

The one or more hardware devices, the one or more storage devices,and/or the computer programs, program code, instructions, or somecombination thereof, may be specially designed and constructed for thepurposes of the example embodiments, or they may be known devices thatare altered and/or modified for the purposes of example embodiments.

A hardware device, such as a computer processing device, may run anoperating system (OS) and one or more software applications that run onthe OS. The computer processing device also may access, store,manipulate, process, and create data in response to execution of thesoftware. For simplicity, one or more example embodiments may beexemplified as one computer processing device; however, one skilled inthe art will appreciate that a hardware device may include multipleprocessing elements and multiple types of processing elements. Forexample, a hardware device may include multiple processors or aprocessor and a controller. In addition, other processing configurationsare possible, such as parallel processors.

Although described with reference to specific examples and drawings,modifications, additions and substitutions of example embodiments may bevariously made according to the description by those of ordinary skillin the art. For example, the described techniques may be performed in anorder different with that of the methods described, and/or componentssuch as the described system, architecture, devices, circuit, and thelike, may be connected or combined to be different from theabove-described methods, or results may be appropriately achieved byother components or equivalents.

When the terms “about” or “substantially” are used in this specificationin connection with a numerical value, it is intended that the associatednumerical value include a tolerance of ±10% around the stated numericalvalue. When ranges are specified, the range includes all valuestherebetween such as increments of 0.1%.

FIG. 1 is a schematic cross-sectional view of an exposure apparatus 99according to some example embodiments of the inventive concepts.

Referring to FIG. 1, the exposure apparatus 99 may be used in (e.g., mayimplement) an optical lithography process to pattern a resist layer 80formed on a substrate 70 via light having a particular (or,alternatively, predetermined) wavelength. The exposure apparatus 99 mayinclude a light source 90 configured to emit light of a particular (or,alternatively, predetermined) wavelength and a reticle 95. The reticle95 may include a photomask 30 configured to perform an expose operationon the resist layer 80 and a pellicle 60 configured to protect thephotomask 30.

To form a minute pattern on the resist layer 80, the light source 90 mayemit light of a short wavelength spectrum of light. In detail, the lightsource 90 may emit light of an extreme ultraviolet ray (EUV) wavelengthspectrum of light having a wavelength of approximately 13.3 nm.

Light of the EUV wavelength spectrum of light emitted from the lightsource 90 enters a reticle 95. The reticle 95 denotes a structure inwhich the photomask 30 and the pellicle 60 are combined. Although notshown, an optical system, such as a collimating lens may further bearranged on an optical path between the light source 90 and the reticle95 so that light of the EUV wavelength spectrum of light emitted fromthe light source 90 becomes uniformly incident onto the reticle 95.

The photomask 30 may be configured to perform an expose operation on theresist layer 80 formed on the substrate 70 by using light of the EUVwavelength spectrum of light emitted from the light source 90. Thephotomask 30 may include a mask substrate 20 and mask patterns 10arranged on a surface of the mask substrate 20 in a particular (or,alternatively, predetermined) pattern. Also, the pellicle 60 may beformed on a lower side of the mask substrate 20 to cover the maskpatterns 10.

The photomask 30 may include a reflection type photomask. In this case,the light of the EUV wavelength spectrum of light emitted from the lightsource 90 may enter the photomask 30 after passing through the pellicle60, and light of a EUV wavelength spectrum of light reflected by thephotomask 30 may enter the resist layer 80 on the substrate 70 afterpassing through the pellicle 60. The mask substrate 20 may include areflective layer that reflects the light of the EUV wavelength spectrumof light, and the mask patterns 10 may include a light absorptionpattern configured to absorb the light of the EUV wavelength spectrum oflight. Although not shown, an optical system, such as a focusing lensfor focusing (e.g., “configured to focus”) the light of the EUVwavelength spectrum of light coming out from the reticle 95, may furtherbe arranged on an optical path between the reticle 95 and the resistlayer 80.

The pellicle 60 is arranged on a lower side of the photomask 30 and isconfigured to protect the photomask 30 from absorbing externalcontaminants, such as dust or resists. For this purpose, the pellicle 60may include a pellicle membrane 40 arranged at a particular (or,alternatively, predetermined) distance from the photomask 30, such thatan intervening space 44 is at least partially defined by the pellicle 60and the photomask 30 and is between the pellicle membrane 40 and thephotomask 30. The pellicle membrane 40 may be spaced by approximately afew mm from the photomask 30. For example, a distance between thepellicle membrane 40 and the photomask 30 may be in a range from about 1mm to about 10 mm.

A frame 50 may be arranged between the pellicle membrane 40 and thephotomask 30. The frame 50 is arranged on an edge region of thephotomask 30 and may support the pellicle membrane 40 to be spaced apartfrom the photomask 30 by a certain distance. For example, the frame 50may have a height in a range from about 1 mm to about 10 mm so that thedistance between the pellicle membrane 40 and the photomask 30 is in arange from about 1 mm to about 10 mm. A layer that constitutes the frame50 will be described below.

In the exposure apparatus 99 having a structure described above, anexposure process is performed (e.g., the exposure apparatus 99 isconfigured to implement an exposure process) such that the light of theEUV wavelength spectrum of light emitted from the light source 90 entersthe photomask 30 after passing through the pellicle membrane 40, andlight of a EUV wavelength spectrum of light reflected by the photomask30 enters the resist layer 80 formed on the substrate 70 after passingthrough the pellicle membrane 40.

In the exposure apparatus 99 of FIG. 1, as an example, the photomask 30is depicted as a reflection photomask., the example embodiments are notlimited thereto, that is, the photomask 30 may be a transmission typephotomask. In this case, the mask substrate 20 may include atransmission layer configured to transmit incident light, and the maskpattern 10 may include an absorption pattern configured to absorbincident light.

The pellicle 60 as illustrated in FIG. 1 may be any of the pelliclesdescribed herein and any of the pellicles illustrated in any of thefigures described herein. Restated, an exposure apparatus 99 accordingto some example embodiments may include a reticle 95 that includes apellicle 60 that is any of the pellicles described herein and any of thepellicles illustrated in any of the figures described herein.

FIG. 2 is a cross-sectional view of a pellicle 100 for a photomask,according to some example embodiments of the inventive concepts.

Referring to FIG. 2, the pellicle 100 may perform the same function (“acommon function”) as the pellicle 60 including the pellicle membrane 40and the frame 50 of FIG. 1. The pellicle 100 may be arranged on a masksubstrate to cover a mask pattern of a photomask.

The pellicle 100 includes a substrate 110, a metal catalyst layer 120 onthe substrate 110, and a pellicle membrane 130. The metal catalyst layer120 is formed on the substrate 110. The metal catalyst layer 120 on thesubstrate 110 may support one or more edge regions 130 e of the pelliclemembrane 130. In other words, the metal catalyst layer 120 and thesubstrate 110 may not be formed at a central region 130 c of thepellicle membrane 130 that is, only the one or more edge regions 130 eof the pellicle membrane 130 may be collectively supported by the metalcatalyst layer 120 and the substrate 110. The substrate 110 and themetal catalyst layer 120 formed in this way may perform in the same wayas the frame 50 of FIG. 1, and when a reticle (e.g., reticle 95) isformed, may surround the mask patterns 10 in combination with thephotomask 30 to at least partially define an intervening space (e.g.,intervening space 44). As described herein, a “central region” of apellicle membrane may be referred to interchangeably as a “centralportion” of the pellicle membrane, and an “edge region” of a pelliclemembrane may be referred to interchangeably as an “edge portion” of thepellicle membrane. In some example embodiments, an edge region 130 e ofthe pellicle membrane 130 may at least partially surround the centralregion 130 c of the pellicle membrane 130. For example, as shown in FIG.2, an edge region 130 e of the pellicle membrane 130 may at leastpartially and/or completely surround the central region 130 c of thepellicle membrane 130.

Restated, the pellicle membrane 130 on the metal catalyst layer 120 mayinclude a two-dimensional (2D) material, the pellicle membrane may havea central region 130 c and an edge region 130 e, the edge region 130 eat least partially surrounding the central region 130 c, and thesubstrate 110 and the metal catalyst layer 120 may collectively supportthe edge region 130 e of the pellicle membrane 130 and may not supportthe central region 130 c of the pellicle membrane 130.

A sum of a height of the substrate 110 and a height of the metalcatalyst layer 120 may be in a range from about 1 mm to about 10 mm sothat the pellicle membrane 130 and the photomask may be separated fromeach other by a particular (or, alternatively, predetermined) distance.

The metal catalyst layer 120 arranged on the substrate 110 may includeat least one of Pt, Cu, Ni, Co, Ag, W, Mo, Pd, and Ru. The metalcatalyst layer 120 may have a thickness of about 100 μm or less, forexample, a thickness greater than about 10 nm and less than about 100μm. In another example, the metal catalyst layer 120 may have athickness greater than about 10 nm and less than about 10 μm.

The pellicle membrane 130 may be formed by (“based on”) directly growinga material on a surface 120 a of the metal catalyst layer 120 (e.g.,growing a material directly on a surface 120 a of the metal catalystlayer 120). The pellicle membrane 130 may include a material having atwo-dimensional (2D) type crystal structure, that is, a 2D material. Forexample, the pellicle membrane 130 may include a 2D material thatincludes at least one of h-BN (hexagonal boron nitride), silicon (Si),phosphorus (P), boron (B), and graphene. The pellicle membrane 130 mayhave a thickness in a range from about 5 n to about 50 nm.

The pellicle membrane 130 may have a high physicochemical durability anda high optical transmittance. For example, the pellicle membrane 130 mayhave an optical transmittance of greater than or equal to about 80%.

A protection film may be formed on at least one surface of both(“opposite”) surfaces 130 a, 130 b of the pellicle membrane 130. The oneor more protection films may reinforce the durability of the pelliclemembrane 130 and may reduce and/or minimize deformation of the pelliclemembrane 130 that may occur due to accumulation of heat in an exposingprocess in which light of a EUV wavelength spectrum of light is used.Also, the one or more protection films may provide a highphysicochemical durability to the pellicle membrane 130 so as not to bedamaged by exposure to light of a EUV wavelength spectrum of light formore than a certain period of time or by a surface cleaning process.

The one or more protection films may include at least one of acarbon-based material, a transition metal dichalcogenide (TMD), Ru, Mo,Si, Zr, B, and SiN. The carbon-based material may include, for example,at least one of amorphous carbon, graphene, nano graphite, carbonnanosheet, carbon nanotube, SiC, and B4C. The TMD may include one ofmetal element, for example, Mo, W, Nb, V, Ta, Ti, Zr, Hf, Tc, Re, Cu,Ga, In, Sn, Ge, and Pb and one of a chalcogen element, for example, S,Se, and Te.

The pellicle membrane 130 and one or more edge regions of the protectionfilms formed on both surfaces of the pellicle membrane 130 may besupported by the metal catalyst layer 120 and the substrate 110, suchthat the metal catalyst layer 120 and the substrate 110 collectivelysupport at least one edge region 130 e of the pellicle membrane 130 anddo not support the central region 130 c of the pellicle membrane 130. Inother words, the metal catalyst layer 120 and the substrate 110 mayperform the same function as the frame 50 of FIG. 1.

FIGS. 3A through 3D are cross-sectional views for explaining a method ofmanufacturing a pellicle for a photomask according to some exampleembodiments of the inventive concepts.

Referring to FIGS. 3A and 3B, the metal catalyst layer 120 is formed onthe substrate 110. The substrate 110 may include a material, such as Si,glass, quartz, or Al₂O₃. The metal catalyst layer 120 may include atleast one of Pt, Cu, Ni, Co, Ag, W, Mo, Pd, and Ru. The metal catalystlayer 120 may have a thickness of 100 μm or less, for example, athickness greater than 10 nm and less than 10 μm.

Referring to FIG. 3C, the pellicle membrane 130 including atwo-dimensional (2D) material is formed on a surface 120 a of the metalcatalyst layer 120. As shown in FIG. 3C, the pellicle membrane 130 maybe formed directly on a surface 120 a of the metal catalyst layer 120.As described herein, in some example embodiments the pellicle membrane130 may be formed indirectly (e.g., not directly) on the metal catalystlayer 120, such that there is an intervening layer (e.g., a protectionlayer 150 as described below) between the metal catalyst layer 120 andthe pellicle membrane 130 formed thereon. When the pellicle membrane 130is formed directly on a surface of a material layer, for example, thesurface 120 a of the metal catalyst layer 120, the pellicle membrane 130may directly be grown on the surface 120 a of the metal catalyst layer120. The pellicle membrane 130 may include a material having atwo-dimensional type crystal structure, that is, a 2D material. Forexample, the pellicle membrane 130 may include at least one of h-BN, Si,P, B, and graphene. Also, the pellicle membrane 130 may have a thicknessin a range from about 5 nm to about 50 nm.

The pellicle membrane 130 may be formed by using a chemical vapordeposition (CVD) method or a physical vapor deposition (PVD) method.

Also, in FIG. 3C, a protection film (not shown) may be formed on thesurface 120 a of the metal catalyst layer 120 before forming thepellicle membrane 130 on the metal catalyst layer 120. After forming theprotection film, the pellicle membrane 130 may be formed on theprotection film, and again a protection film (e.g., protection film 150as shown in FIG. 3D) may be formed on a surface 130 a of the pelliclemembrane 130. That is, the protection films may be formed on bothsurfaces 130 a, 130 b of the pellicle membrane 130, and/or protectionfilm 150 may be formed between pellicle membrane 130 and metal catalystlayer 120 in FIG. 3C, in addition or in alternative to the protectionfilm 150 illustrated on surface 130 a of the pellicle membrane 130 inFIG. 3D. However, the example embodiments are not limited thereto, thatis, the protection film may be formed only on a surface (e.g., 130 aand/or 130 b) of the pellicle membrane 130. In this way, when aprotection film is formed on at least one surface of the pelliclemembrane 130, the protection film may have a surface roughness similarto that of the pellicle membrane 130.

Referring to FIG. 3D, at least inner regions 110 b and 120 b of thesubstrate 110 and the metal catalyst layer 120, respectively, thatsupport a central region 130 c of the pellicle membrane 130 are etched(e.g., selectively removed), such that the remainder regions of thesubstrate 110 and the metal catalyst layer 120 collectively support theone or more edge regions 130 e of the pellicle membrane 130 and do notsupport the central region 130 c of the pellicle membrane 130. Thus, theone or more edge regions 130 e of the pellicle membrane 130 may beunderstood to be supported by the metal catalyst layer 120 and thesubstrate 110, and the central region 130 c of the pellicle membrane 130may be understood to be unsupported by the metal catalyst layer 120 andthe substrate 110. As shown in FIG. 3D, the remainder regions of thesubstrate 110 and the metal catalyst layer 120 that collectively supportthe one or more edge regions 130 e of the pellicle membrane 130 and donot support the central region 130 c of the pellicle membrane 130 maysimply be referred to as the substrate 110 and the metal catalyst layer120. The substrate 110 and the metal catalyst layer 120 may be etchedbased on using at least one of a mechanical etching method, a dryetching method, and a wet etching method.

Through the etching process, the substrate 110 and the metal catalystlayer 120 may perform as a frame that supports one or more edge regions130 e of the pellicle membrane 130 and does not support central region130 c of the pellicle membrane 130. As referred to herein, and as shownin at least FIG. 3D, a layer that is described as “not” supporting thecentral region of a pellicle membrane will be understood to be directlysupporting the one or more edge regions of the pellicle membrane andindirectly supporting the central region of the pellicle membranethrough the one or more edge regions of the pellicle membrane while notdirectly supporting the central region of the pellicle membrane. Forexample, as shown in FIG. 3D, the metal catalyst layer 120 and thesubstrate 110 will be understood to collectively “directly” support theone or more edge regions 130 e of the pellicle membrane 130 andcollectively do not “directly” support the central region 130 c of thepellicle membrane 130 but instead “indirectly” support the centralregion 130 c through the one or more edge regions 130 e, and thus willbe understood to collectively support the one or more edge regions 130 eof the pellicle membrane 130 and to not support the central region 130 cof the pellicle membrane 130.

FIG. 4 is a cross-sectional view of a pellicle 200 for a photomask,according to some example embodiments of the inventive concepts.

Referring to FIG. 4, the pellicle 200 may perform the same function asthe pellicle 60 that includes the pellicle membrane 40 and the frame 50.

The pellicle 200 includes a substrate 210, a barrier layer 220 on thesubstrate 210, a metal catalyst layer 230 on the barrier layer 220, anda pellicle membrane 240. As shown in FIG. 4, the barrier layer 220 maybe between the substrate 210 and the metal catalyst layer 230. Thesubstrate 210, the barrier layer 220, and the metal catalyst layer 230may support only one or more edge regions 240 e of the pellicle membrane240 and not a central region 240 c of the pellicle membrane 240 (e.g.,only indirectly support the central region 240 c via the one or moreedge regions 240 e).

The barrier layer 220 formed on the substrate 210 may solidly bond themetal catalyst layer 230 to the substrate 210. Through this, durabilityof the pellicle 200 may be increased. The barrier layer 220 may includeat least one of SiO₂, Si₃N₄, TiN, and TaN.

The metal catalyst layer 230 formed on the barrier layer 220 may includeat least one of Pt, Cu, Ni, Co, Ag, W, Mo, Pd, and Ru.

The structure and materials of the substrate 210, the metal catalystlayer 230, and the pellicle membrane 240 except the barrier layer 220are the same as the structure and materials described with reference toFIG. 2, and thus, the descriptions thereof will be omitted.

FIGS. 5A through 5E are cross-sectional views for explaining a method ofmanufacturing a pellicle for a photomask, according to some exampleembodiments of the inventive concepts.

Referring to FIGS. 5A and 5B, the barrier layer 220 is formed on thesubstrate 210. The substrate 210 may include a material, such as Si,glass, quartz, or Al₂O₃. The barrier layer 220 may include at least oneof SiO₂, Si₃N₄, TiN, and TaN.

Referring to FIG. 5C, the metal catalyst layer 230 is formed on thebarrier layer 220. The metal catalyst layer 230 may include at least oneof Pt, Cu, Ni, Co, Ag, W, Mo, Pd, and Ru.

Referring to FIG. 5D, the pellicle membrane 240 including a 2D materialis (directly or indirectly) formed on a surface 230 a of the metalcatalyst layer 230. The pellicle membrane 240 may be formed by using aCVD method or a PVD method.

Referring to FIG. 5E, at least inner regions 210 b, 220 b, 230 b of thesubstrate 210, the barrier layer 220, and the metal catalyst layer 230that support a central region 240 c of the pellicle membrane 240,respectively are etched. The substrate 210, the barrier layer 220, andthe metal catalyst layer 230 may be etched based on using at least oneof a mechanical etching method, a dry etching method, and a wet etchingmethod.

Through the etching process, and as shown in FIG. 5E, the remainderregions of the substrate 210, the barrier layer 220, and the metalcatalyst layer 230 may perform as a frame that (“directly”) supports oneor more edge regions 240 e of the pellicle membrane 240 and does not(“directly”) support central region 240 c of the pellicle membrane 240.

FIG. 6 is a cross-sectional view of a pellicle 300 for a photomask,according to some example embodiments of the inventive concepts.

Referring to FIG. 6, the pellicle 300 may perform the same function asthe pellicle 60 including the pellicle membrane 40 and the frame 50 ofFIG. 1.

The pellicle 300 includes a substrate 310, a barrier layer 320 on thesubstrate 310, and a pellicle membrane 330. The substrate 310 and thebarrier layer 320 may perform as the frame 50 of FIG. 1, that is, thesubstrate 310 and the barrier layer 320 support one or more edge regions330 e of the pellicle membrane 330.

FIGS. 7A through 7F are cross-sectional views for explaining a method ofmanufacturing a pellicle for a photomask, according to some exampleembodiments of the inventive concepts.

Referring to FIGS. 7A and 7B, the barrier layer 320 is formed on thesubstrate 310. The substrate 310 may include Si, glass, quartz, orAl₂O₃. The barrier layer 320 may include at least one of SiO₂, Si₃N₄,TiN, and TaN.

Referring to FIG. 7C, a metal catalyst layer 340 is formed on thebarrier layer 320. The metal catalyst layer 340 may include at least oneof Pt, Cu, Ni, Co, Ag, W, Mo, Pd, and Ru.

Referring to FIG. 7D, the pellicle membrane 330 including a 2D materialis (directly or indirectly) formed on a lower side (e.g., lower surface340 f) of the metal catalyst layer 340 (e.g., between the metal catalystlayer 340 and the barrier layer 320). The pellicle membrane 330 mayinclude a material having a two-dimensional (2D) type crystal structure,that is, a 2D material. For example, the pellicle membrane 330 mayinclude at least one of h-BN, Si, P, B, and graphene. When a 2D materialfor forming the pellicle membrane 330 is deposited on the metal catalystlayer 340 by using a CVD method or a PVD method, the 2D material maypenetrate into the metal catalyst layer 340. At this point, through acontrol of a material that constitutes the barrier layer 320 and acontrol of process temperature and pressure, the pellicle membrane 330including a 2D material may be formed on a lower side of the metalcatalyst layer 340.

Referring to FIG. 7E, the metal catalyst layer 340 is removed. To removethe metal catalyst layer 340, at least one of a mechanical etchingmethod, a dry etching method, and a wet etching method may be used.Restated, the metal catalyst layer 340 may be removed based on using atleast one of a mechanical etching method, a dry etching method, and awet etching method.

Referring to FIG. 7F, at least inner regions 310 b, 320 b of thesubstrate 310 and the barrier layer 320, respectively, that support acentral region 330 c of the pellicle membrane 330 are etched. Thesubstrate 310 and the barrier layer 320 may be etched based on using atleast one of a mechanical etching method, a dry etching method, and awet etching method.

Through the above etching process, the substrate 310 and the barrierlayer 320 may (“directly”) support one or more edge regions 330 e of thepellicle membrane 330 and may not (“directly”) support central region330 c of the pellicle membrane.

FIGS. 8A through 8C are cross-sectional views for explaining a method ofmanufacturing a pellicle for a photomask according to some exampleembodiments of the inventive concepts.

In some example embodiments, the metal catalyst layer may perform as asubstrate (or, restated, the substrate may perform as the metal catalystlayer), such that the substrate as an element separate from the metalcatalyst layer is omitted from the pellicle.

Referring to FIG. 8A, a substrate 410 that is configured to perform as ametal catalyst layer is provided. The substrate 410 may include amaterial, including at least one of Pt, Cu, Ni, Co, Ag, W, Mo, Pd, andRu. In some example embodiments, the substrate 410 may have a thicknessof 100 μm or less, for example, a thickness greater than 10 nm and lessthan 10 μm. Accordingly, the substrate 410 may be referred tointerchangeably herein as a “metal catalyst layer” having some or all ofthe properties and/or characteristics of the metal catalyst layersdescribed herein.

Referring to FIG. 8B, the pellicle membrane 430 including atwo-dimensional (2D) material is directly formed on a surface 410 a ofthe substrate 410. The pellicle membrane 430 may include a materialhaving a two-dimensional type crystal structure, that is, a 2D material.For example, the pellicle membrane 430 may include at least one of h-BN,Si, P, B, and graphene. Also, the pellicle membrane 430 may have athickness in a range from about 5 nm to about 50 nm.

The pellicle membrane 430 may be formed by using a chemical vapordeposition (CVD) method or a physical vapor deposition (PVD) method.

Also, in FIG. 8B, a protection film (not shown) may be formed on thesurface 410 a of the substrate 410 before forming the pellicle membrane430 on the substrate 410. After forming the protection film, thepellicle membrane 430 may be formed on the protection film, and again aprotection film may be formed on a substrate-distal surface of thepellicle membrane 430. That is, the protection films may be formed onopposite surfaces of the pellicle membrane 430. However, the exampleembodiments are not limited thereto, that is, the protection film may beformed only on an individual surface of the pellicle membrane 430. Inthis way, when a protection film is formed on at least one surface ofthe pellicle membrane 430, the protection film may have a surfaceroughness similar to that of the pellicle membrane 430.

As shown in FIG. 8B, the pellicle membrane 430 may be formed on alimited region 410 b of the surface 410 a of the substrate 410, suchthat an edge region 410 e of the substrate 410 is exposed by thepellicle membrane 430. The pellicle membrane 430 may be formed to have aparticular (or, alternatively, predetermined) shape and/or size on thelimited region 410 b of the substrate 410.

Referring to FIG. 8C, at least an inner region 410 c of the limitedregion 410 b of the substrate 410 that supports a central region 430 cof the pellicle membrane 430 is etched (e.g., selectively removed),thereby leaving a remainder region 410 r of the limited region 410 b ofthe substrate 410. In addition, as further shown in FIG. 8C, the one ormore edge regions 410 e of the substrate 410 that are exposed by thepellicle membrane 430 may be etched, so that outer side surfaces 430 dand 410 d of the pellicle membrane 430 and the substrate 410 are flushor substantially flush (e.g., flush within manufacturing tolerancesand/or material tolerances). The substrate 410 may be etched based onusing at least one of a mechanical etching method, a dry etching method,and a wet etching method.

Through the etching process, the remainder region 410 r of the substrate410 may perform as a frame that (“directly”) supports one or more edgeregions 430 e of the pellicle membrane 430 and does not (“directly”)support central region 430 c of the pellicle membrane 430 (e.g.,indirectly supports the central region 430 c via the one or more edgeregions 430 e). Thus, as shown in FIG. 8C, a pellicle 800 that includesthe pellicle membrane 430 and the remainder region 410 r of thesubstrate 410 may be formed.

In the methods of manufacturing a pellicle for a photomask according tosome example embodiments of the inventive concepts, a pellicle membraneis not formed by a conventional transfer method. In the methodsdescribed above, a pellicle membrane is directly formed on a materiallayer using a growth method.

For example, when the pellicle membrane is the pellicle membrane 130 ofFIG. 3C and the material layer is the metal catalyst layer 120 and whenthe pellicle membrane 130 is formed by a conventional transfer methodand when the pellicle membrane 130 is directly formed by a growthmethod, there is difference of an adhesive power between the pelliclemembrane 130 and the metal catalyst layer 120.

According to an experimental example, an adhesive power between thepellicle membrane 130 and the metal catalyst layer 120 was about 180 MPawhen the pellicle membrane 130 is formed on the metal catalyst layer 120using a conventional transfer method.

On the other hand, the adhesive power between the pellicle membrane 130and the metal catalyst layer 120 was about 1200 MPa when the pelliclemembrane 130 is directly formed on the metal catalyst layer 120 using agrowth method.

The experimental result indicates that the adhesive power between thepellicle membrane 130 and the metal catalyst layer 120 when the pelliclemembrane 130 is directly formed on the metal catalyst layer 120 using agrowth method is largely increased than when the pellicle membrane 130is formed on the metal catalyst layer 120 using a conventional transfermethod.

In the experimental example, a silicone substrate was used as thesubstrate 110, an Ni—Cu alloy was used as the metal catalyst layer 120and graphene having thickness less than 100 nm was used as the pelliclemembrane 130. Also, a PMMA supported wet transfer method was used as theconventional transfer method and a CVD method was used as the growthmethod.

According to the inventive concepts, a pellicle membrane that protects aphotomask from external contaminants may have high physicochemicaldurability without being damaged by exposure to light of a EUVwavelength spectrum of light for more than a certain period of time orby a surface cleaning process.

Also, since a pellicle membrane is formed by selectively removing ametal catalyst layer after directly growing a 2D material on the metalcatalyst layer, the pellicle membrane may be formed without using atransfer process (e.g., without transferring the pellicle membrane ontothe metal catalyst layer).

Also, the metal catalyst layer and the substrate, central regionsthereof are selectively removed may be used as a frame for supportingthe pellicle membrane.

Durability of the pellicle membrane may further be increased anddeformation of the pellicle membrane that may cause due to heataccumulation may be reduced and/or minimized by forming a protectionfilm on at least a surface of the pellicle membrane, and thus, alifetime of the pellicle may be increased.

The example embodiments are examples, and thus, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the inventive concepts. Therefore, the embodiments should beconsidered in descriptive sense only and not for purposes of limitation.For example, each constituent element that is described as a singularform may be embodied in distribution forms. Also, constituent elementsthat are described in distribution forms may be embodied in a combinedform.

Therefore, the scopes of the embodiments are defined not by the detaileddescription but by the appended claims, and all differences within thescope will be construed as being included in the example embodiments.

What is claimed is:
 1. A pellicle configured to protect a photomask, thepellicle comprising: a substrate; a metal catalyst layer on thesubstrate; a barrier layer only between the substrate and the metalcatalyst layer; and a pellicle membrane on the metal catalyst layer, thepellicle membrane including a two-dimensional (2D) material, thepellicle membrane having a central region and an edge region, the edgeregion at least partially surrounding the central region, wherein thesubstrate and the metal catalyst layer collectively support the edgeregion of the pellicle membrane and do not support the central region ofthe pellicle membrane.
 2. The pellicle of claim 1, wherein the barrierlayer is only between an upper surface of the substrate and a bottomsurface of the metal catalyst layer.
 3. The pellicle of claim 1, whereinthe metal catalyst layer has a thickness in a range from about 10 nm toabout 100 μm.
 4. The pellicle of claim 1, wherein the metal catalystlayer has a thickness in a range from about 10 nm to about 10 μm.
 5. Thepellicle of claim 2, wherein the barrier layer is in direct contact withthe entire upper surface of the substrate and the entire bottom surfaceof the metal catalyst layer.
 6. The pellicle of claim 1, wherein thebarrier layer includes at least one of SiO2, Si3N4, TiN, and TaN.
 7. Thepellicle of claim 1, wherein the 2D material includes at least one ofh-BN, Si, P, B, and graphene.
 8. The pellicle of claim 7, wherein thepellicle membrane has a thickness in a range from about 5 nm to about 50nm.
 9. The pellicle of claim 1, wherein the metal catalyst layerincludes at least one of Pt, Cu, Ni, Co, Ag, W, Mo, Pd, and Ru.
 10. Thepellicle of claim 1, wherein the pellicle membrane has an opticaltransmittance greater than or equal to about 80%.
 11. The pellicle ofclaim 1, wherein a sum of a height of the metal catalyst layer and aheight of the substrate is in a range from about 1 mm to about 10 mm.12. The pellicle of claim 1, further comprising: a protection film on atleast one surface of the pellicle membrane.
 13. The pellicle of claim12, wherein the protection film includes at least one of a carbon-basedmaterial, a transition metal dichalcogenide (TMD), Ru, Mo, Si, Zr, B,and SiN.
 14. A method of manufacturing a pellicle configured to protecta photomask, the method comprising: forming a barrier layer on asubstrate; forming a metal catalyst layer on the substrate such that thebarrier layer is only between the substrate and the metal catalystlayer; forming a pellicle membrane on the metal catalyst layer, thepellicle membrane including a two-dimensional (2D) material, thepellicle membrane including a central region and an edge region, theedge region at least partially surrounding the central region; andetching at least inner regions of the substrate and the metal catalystlayer that support the central region of the pellicle membrane, suchthat the substrate and the metal catalyst layer collectively support theedge region of the pellicle membrane and do not support the centralregion of the pellicle membrane.
 15. The method of claim 14, wherein thebarrier layer is only between an upper surface of the substrate and abottom surface of the metal catalyst layer.
 16. The method of claim 15,wherein the barrier layer is in direct contact with the entire uppersurface of the substrate and the entire bottom surface of the metalcatalyst layer.
 17. The method of claim 14, further comprising: forminga protection film on at least one surface of the pellicle membrane. 18.The method of claim 14, wherein the forming of the pellicle membraneincludes forming the pellicle membrane directly on a surface of themetal catalyst layer.
 19. The method of claim 14, wherein the etchingincludes etching the substrate and the metal catalyst layer based onusing at least one of a mechanical etching method, a dry etching method,and a wet etching method.
 20. A reticle, comprising: a photomaskincluding a mask pattern; and a pellicle including a substrate, a metalcatalyst layer on the substrate and surrounding the mask pattern, abarrier layer only between the substrate and the metal catalyst layer,and a pellicle membrane including a two-dimensional (2D) material, thepellicle membrane including a central region and an edge region, theedge region at least partially surrounding the central region, the edgeregion supported by the substrate and the metal catalyst layer, thecentral region unsupported by the substrate and the metal catalystlayer.
 21. The reticle of claim 20, wherein the photomask is spacedapart from the pellicle membrane by a distance in a range from about 1mm to about 10 mm.
 22. The reticle of claim 20, wherein the metalcatalyst layer has a thickness in a range from about 10 nm to about 100μm.
 23. The reticle of claim 20, wherein the metal catalyst layer has athickness in a range from about 10 nm to about 10 μm.
 24. The reticle ofclaim 20, wherein the barrier layer is only between an upper surface ofthe substrate and an bottom surface of the metal catalyst layer, andwherein the barrier is in direct contact with the entire upper surfaceof the substrate and the entire bottom surface of the metal catalystlayer.
 25. The reticle of claim 20, wherein the barrier layer includesat least one of SiO2, Si3N4, TiN, and TaN.
 26. The reticle of claim 20,wherein the 2D material includes at least one of h-BN, Si, P, B, andgraphene.
 27. The reticle of claim 26, wherein the pellicle membrane hasa thickness in a range from about 5 nm to about 50 nm.
 28. The reticleof claim 20, wherein the metal catalyst layer comprises at least one ofPt, Cu, Ni, Co, Ag, W, Mo, Pd, and Ru.
 29. The reticle of claim 20,wherein the pellicle membrane has an optical transmittance greater thanor equal to about 80%.
 30. The reticle of claim 20, wherein the pellicleincludes a protection film on at least one surface of the pelliclemembrane.
 31. The reticle of claim 30, wherein the protection filmincludes at least one of a carbon-based material, a transition metaldichalcogenide (TMD), Ru, Mo, Si, Zr, B, and SiN.